Growth of Internet traffic for both residential and business has allowed service providers to find ways to generate more revenues and position themselves to benefit from the addition of more and more services offered over the Internet. A lot of these services such as HDTV, gaming and real-time applications are characterized by two features. One is their stringent network requirements in terms of delay, jitter and demand for high bandwidth, and the other is their burstiness, their traffic routing patterns and unpredictable bandwidth demand. This has resulted to an operational challenge for the service providers to predict bandwidth requirements at many of their sites. It is noted that one way to cope with this challenge is provisioning high bandwidth connectivity to each one of the sites. This results in both increase in capital expenditure and network complexity.
As a result of above challenge, service providers will benefit from all optical agile networks that support reconfiguration of network resources. As part of all optical networks (AON), Reconfigurable Optical Add/Drop Multiplexer (ROADM) offers bandwidth connectivity to any site and allows grooming of node add/drop traffic. ROADMs enable transparent connectivity of many metro nodes in both ring and mesh connectivity. By definition, ROADM is an optical network element that routes optical signals directly and avoids Optical-Electrical-Optical (OEO) conversion. Integration of ROADMs into the present WDM networks is of critical value as they provide the pay-as-you-grow capability and flexibility to provision wavelengths dynamically. This allows ROADM to both pass through any separate wavelength between WDM node lines interfaces and to add/drop any separate wavelength from WDM line interfaces to add/drop ports.